Transparent cylinders are widespread in various fields such as laboratory glassware in the form of beaker or metering cylinder, food container in the form of tub or bottle or medical glassware in the form of vial, cartridge or syringe. Whatever the field considered, these different containers require a high degree of quality and cleanliness, especially in the medical field where quality and/or cleanliness issues may have a direct impact on the safety of patients and medical staff.
Indeed, transparent cylinders, made of glass or plastic, are produced by complex manufacturing processes that may result in the formation of particles or defects in the material itself or on its surface. A careful inspection step of such transparent cylinders is thus required before delivery to the customer.
Such an inspection step is usually made automatically by cameras using a back end light positioned behind the transparent cylinder. However, this kind of inspection does not allow the detection of small-size cosmetic defects and/or glass particles. Furthermore, such an inspection system is not specific as it cannot differentiate the different types of observed defects.
There is therefore a need for a reliable system able to detect small glass particles and cosmetic defects.